CN114286781A

CN114286781A - Electric drive system with cooling device for watercraft, such as surfboards or paddles

Info

Publication number: CN114286781A
Application number: CN202080060091.1A
Authority: CN
Inventors: 尼古拉斯·坤德孜
Original assignee: Sports Concept Group
Current assignee: Sports Concept Group
Priority date: 2019-08-28
Filing date: 2020-08-28
Publication date: 2022-04-05
Anticipated expiration: 2040-08-28
Also published as: TW202114908A; JP2022546377A; TWI780474B; WO2021038037A1; US20220324538A1; AU2020339725A1; FR3100222A1; EP4021793A1

Abstract

The present invention relates to a motorized system for an electrically-assisted boat intended to allow the transport of the user over water, in particular for use in the field of surfboards, paddles or sailboards, and canoes or canoes. The electric motorization system is configured to be connected to a source of electric energy and comprises, on the one hand, a watertight housing 1 intended to be integrated in or on a vessel, wherein a rotor 2 and stators 3, 7 are arranged in the housing 1; on the other hand, a shaft 4 is included which is connected to the rotor 2 at a first end and protrudes outside the housing 1 in a watertight manner at a second end opposite to the first end thereof. The shaft 4 may be connected at its second end to a propulsion device of the vessel, such as a propeller, so that when the system is powered, the rotor 2 rotates and drives the shaft 4 with the rotation. The system also comprises cooling means 5 which themselves comprise at least one first elongated component 5 at least partially made of metal, a first end of which is arranged inside the casing 1, the elongated component 5 protruding outside the casing 1 in a watertight manner at a second end opposite to its first end, so as to allow heat to be conducted from the inside of the casing 1 to the outside along the first elongated component 5.

Description

Electric drive system with cooling device for watercraft, such as surfboards or paddles

Technical Field

The present invention relates to a motorized system for an electrically-assisted watercraft intended to allow the user to transport on water. It finds particular application in the field of surfboards, paddles and even sail surfboards, and in the field of kayaks or canoes.

Background

For example, surfboards are intended to allow a user to slide on the surface of water under the propulsive action provided by the waves. Typically, a user lying on the board uses his arms to provide the propulsive force necessary to bring the board to the area where the waves are or are being formed, in the absence of waves in the given area where the user is located.

Another example includes paddles, which as such are intended to allow a user to slide over the water under the propulsive action of the equipped paddle. Like surfboards, paddle boards also allow a user to plane on water under the propulsive action provided by the waves.

There are also other examples of allowing a user to navigate over water, by mechanical propulsion action provided directly by the user himself, or by using devices such as one or more paddles or oars, and/or by providing propulsion through environments such as wind or waves.

To facilitate the use of these vessels, especially in areas or times where the mechanical propulsion provided by the user or the environment is insufficient, these vessels may be equipped with an electric auxiliary device, i.e. an electric motor system driving a mechanical propulsion device, such as a propeller.

Generally, propeller boat propulsion requires the propeller to rotate at a lower speed to avoid propeller cavitation.

Traditionally, two types of electric motors can be used to drive the propeller in rotation: an "inner rotor" type motor, in which the inner core rotates within a fixed outer cage, and an "outer rotor" or rotating cage type motor, in which the outer cage rotates around the fixed inner core.

The "internal rotor" type motor can be cooled relatively easily, since the external part is fixed, it can be in contact with a cooling system provided for this purpose. However, these motors typically rotate very fast, and therefore require the use of a speed reducer to avoid the cavitation described above. This results in a loss of efficiency and increased mechanical complexity, with a corresponding increase in maintenance and cost.

For a given outer diameter, the "outer rotor" type of motor rotates at a lower speed than the "inner rotor" type of motor, thus limiting cavitation without the complications associated with the use of a reducer as described in the previous paragraph. In fact, with the "outer rotor" type motor, it is possible to maximize the diameter of interaction between the coils of the fixed stator, which are located in the center, and the rotor magnets, which rotate externally. Thus, the use of an "outer rotor" type motor in a watertight closed housing makes it possible to obtain a propeller that rotates more slowly without using a reducer. However, unlike "inner rotor" type motors, these "outer rotor" type motors are difficult to cool while rotating externally and therefore cannot be in contact with conventional cooling systems (e.g., cold wall).

Conventional solutions for cooling "external rotor" type motors, such as the use of water circulation within the stationary parts of the motor, are not satisfactory. In fact, they require the presence of pipes, water inlets and water outlets inside the motor, which is complex to implement.

Disclosure of Invention

Therefore, in particular, one of the objects of the present invention is to solve the above problems. It is therefore an object of the present invention, inter alia, to propose an electric system for a watercraft, such as a surfboard or a paddle board, which is configured to be connected to electric energy.

The system comprises a watertight housing intended to be integrated into or on a vessel, in which housing a rotor and a stator are arranged, and a shaft connected to a motor by a first end and protruding outside the housing in a watertight manner by a second end opposite to the first end.

The shaft is adapted to be connected by its second end to a propulsion device of the vessel, such as a propeller, so that when the system is supplied with electric energy, the rotor starts to rotate in rotation and drives the shaft.

The system also includes a cooling device. These cooling means comprise at least a first elongated component, at least partly of metal, the first end of which is arranged inside the housing. The elongated member protrudes outside the housing in a watertight manner through a second end opposite to its first end, thereby allowing heat to be conducted along said first elongated member from inside the housing to outside the housing.

According to some embodiments, taken alone or in all technically possible combinations, the system also comprises one or more of the following features:

a first end of the first elongated member is secured to the stator;

the stator comprises at least one fastening element, for example a fastening plate, and the first end of the first elongated component is connected to said fastening element;

the first elongated member includes at least a first portion, such as a rod, integrally formed with at least a portion of the stator;

the first elongated member comprises at least a first portion, such as a rod, pressed into a housing provided in the stator, said housing comprising a paste-like heat conducting material, such as a heat conducting silicone;

at least a first portion of the first elongated member is a rod having a substantially circular cross-section;

the first elongated member is a rod having a circular cross-section, which rod protrudes from the housing in a watertight manner by means of an O-ring;

the system comprises an electronic control unit configured to control the operation and the power supply of the system and fastened to the stator so as to form a thermal path between the control unit and the first elongated component to allow the dissipated heat to be conducted by the control unit to the outside of the casing along said thermal path and the first elongated component;

the system comprises an electronic control unit arranged inside the casing and configured to control the operation and power supply of the system, the cooling means comprising at least one second elongated component at least partially metallic, fixed to the casing by a first end and protruding outside the casing in a watertight manner by a second end opposite to its first end to allow heat conduction from the control unit along the second elongated component to the outside of the casing;

at least a portion of the second elongated member is a rod having a generally circular cross-section;

the second elongated member is a rod having a circular cross-section, which rod protrudes from the housing in a watertight manner by means of an O-ring;

the second ends of the first and/or second elongated members having slats spaced apart and formed parallel to the axis of the first or second elongated member, respectively;

the rotor includes a rotating cage and the stator includes a stationary core disposed within the cage.

According to a second aspect, the invention also relates to a watercraft with electric power assistance, such as a surfboard or a paddle board, comprising a propulsion device capable of allowing the watercraft to advance on or in water, and an electric energy source.

The watercraft also comprises an electric system as described above, with its watertight housing integrated on or in the watercraft, and its shaft connected by its second end to the propulsion means, thereby allowing driving of the watercraft propulsion means when supplied with electric energy from said electric power source, and cooling of the electric system by heat exchange between the second end of the first elongated member and the surrounding water.

The motorized system of the invention thus makes it possible to obtain an electrically assisted watercraft, whose propulsion does not require mechanical parts, such as reduction gears, which are complex, expensive and require special maintenance, nor cooling devices, which are complex, expensive and require special maintenance.

Indeed, with the system of the present invention, the removal of heat is accomplished along a thermal path directed by the elongated member. This thermal path leads from the inside of the waterproof housing of the motor to the outside, where the heat escapes into the surrounding water.

The features and advantages of the present invention will appear on reading the following description, given by way of example only and not by way of limitation, with reference to the accompanying drawings, in which:

FIG. 1: a first exemplary schematic of a system according to the invention outside its watertight housing;

FIG. 2: fig. 1 is a schematic longitudinal section of an example of the system integrated into its watertight housing and connected to the propulsion means of a ship;

FIG. 3: fig. 1 is a schematic perspective view of an example of the system integrated into its watertight housing and connected to the propulsion means of a ship;

FIG. 4: a vessel according to the invention incorporates an exemplary schematic of the system of figure 1;

FIG. 5: a schematic longitudinal section of a second example of a system according to the invention, integrated into its watertight housing and connected to the propulsion means of a ship;

FIG. 6: fig. 5 is a schematic perspective view of an example.

Referring to all of the figures, particularly fig. 3, 4 and 6, the electro-motorization system for the vessel 30 is configured to be connected to a source of electrical energy (not shown), such as a battery, also arranged on or in the vessel 30.

As shown in the example of fig. 4, the system comprises a watertight housing 1 for integration on or in an electric auxiliary vessel 30. In this example, the watercraft 30 is of the surfboard or paddle board type.

The boat 30 comprises propulsion means 20 for allowing it to travel in the water, such as a propeller 20, connected to one end of a shaft 4 of a motorized system, which will be described in detail later, the other end of the shaft 4 being arranged inside the casing 1 and therefore not visible in fig. 4. The vessel 30 also includes a source of electrical energy, not shown, as described above.

The first elongated component 5 of the cooling device of the motorized system, and possibly the second elongated component 6 in the example of fig. 6, which will also be described in detail later, project with one of their ends from the casing and with their other end arranged inside the casing 1 and therefore not visible in fig. 3, 4 and 6.

The entire motorized system is integrated into the vessel 30 so that the end of the first elongated component 5 (and possibly the second elongated component 6) protruding from the hull 1 is located in the surrounding water when the vessel 30 is in or on water.

Thus, when the motorized system is powered by an electric energy source, the propulsion device 20 is driven by the shaft 4 and the motorized system can be cooled by heat transfer between the end of the first elongated assembly 5 (and possibly the second elongated assembly 6 protruding from the casing 1) and the surrounding water.

In the example of fig. 4, 5 and 6, in particular, the casing 1 is closed by a wall 15, the shaft 4 and the first elongated component 5 (and possibly the second elongated component 6) projecting in a watertight manner from the wall 15 and extending beyond this wall 15 to form a turbine in which the propulsion device 20 is both protected and operative.

The wall 15 is inclined relative to the longitudinal axis of the shaft 4 and vessel 30 so as not to create surface disruptions relative to the main surface of the vessel 30 which would be detrimental to the hydrodynamics and performance of the propulsion device 20.

In the example of fig. 3, 4 and 6, the end of the first elongated component 5 (and possibly the second elongated component 6) that protrudes from the casing 1 is flush with the surface of the wall 15. Longer protrusions are not necessary to obtain the desired cooling effect and may again be detrimental to the fluid dynamics and performance of propulsion device 20. Furthermore, when the wall 15 is inclined as described above, the end of the first elongated member 5 (possibly the second elongated member 6 protruding from the housing 1) may be chamfered so that it follows the inclined surface of the wall 15.

In a variant embodiment, the turbine part of the hull 1 can be omitted very simply, the part of the shaft 4 protruding from the hull 1 and the propulsion device 20 being housed in a hull provided in the vessel 30 (extending in the hull 1), even beyond any hull of the vessel 30.

Alternatively, the turbine component may be present but separate from the housing 1.

With reference to all the figures, in particular to figures 1, 2 and 5, the motorized system comprises a rotor 2 and a

stator

3, 7 arranged inside a watertight housing 1. The shaft 4 is connected to the rotor 2 by a first end and protrudes outside the housing 1 in a watertight manner by a second end opposite the first end, so as to be connectable to the propulsion device 20 of the watercraft 30 as described above. A sealing device 14 of the gasket type is provided to ensure a watertight seal of the casing 1 at the level of the passage of the shaft 4.

Thus, when the system is powered, the rotor 2 starts to rotate and in that rotation drives the shaft 4, which ultimately allows the propulsion device 20 to rotate and thus propel the watercraft 30.

A cooling device 5 (in the examples of fig. 1 to 4) or a cooling device 5, 6 (in the examples of fig. 5 and 6) is provided. These means 5, 6 comprise one or more

elongated members

5, 6, at least partly of metal, the respective first ends of which are arranged inside the housing 1. These

elongated members

5, 6 also project outside the casing 1 in a watertight manner through respective second ends opposite to their respective first ends. A gasket-

type sealing device

13 or 16, respectively, is provided to ensure the tightness of the casing 1 at the level of the respective channel of the

elongated assembly

5, 6.

Thus, the heat generated inside the casing by the operation of the motorized system, in particular the rotation of the rotor 2, is transferred from the inside to the outside of the casing 1 along the

elongated members

5, 6.

In the example shown in the figures, the first end of the first elongated member 5 is fixed to the

stator

3, 7.

Strictly speaking, the

stator

3, 7 may comprise a stator part 3 and a fastening element 7, for example a fastening plate 7. In this case, preferably, the first end of the first elongated member 5 is connected to the fastening element 7.

The first elongated member 5 comprises at least a first portion, such as a rod 5, which is integrally formed with at least a part of the

stator

3, 7.

Alternatively, the first elongated member 5 comprises at least a first part, such as a rod 5, which is pressed into a housing provided in the

stator

3, 7. In this case, the housing comprises a thermally conductive paste-like material, such as a thermally conductive silicone gel.

In the example shown in the figures, the first elongated member 5, whether it is formed integrally with any part of the

stator

3, 7 or pressed into a housing provided in the

stator

3, 7, is formed integrally by the heat conducting metal bar 5.

The electronic control unit 10 is provided and configured to control the operation and power supply of the motorized system.

Such a control unit usually comprises a microcontroller in an electronic circuit formed on the electronic card 11.

The control unit 10 may be fixed to the

stator

3, 7, for example by the fixing bracket 12 itself being directly connected to the stator part 3 or the fixing element 7. In this case, the electronic card 11 is supported by the fixed support 12 when connected by connection means, in particular electrically, to the

stators

3, 7.

Thus, a thermal path is formed between the control unit 10 and the first elongated member 5, so that the latter also ensures cooling of the control unit 10. In fact, this configuration allows the heat emitted by the control unit 10 to be transferred to the outside of the casing 1 along this thermal path and the first elongated component 5.

Alternatively or additionally, as shown in the example shown in fig. 5 and 6, the cooling means 5, 6 of the motorized system comprise at least a second elongated component, in this case the elongated component 6, as already described above.

Just like the first elongated member 5, the second elongated member 6 is at least partially metallic. It is also fixed to the control unit 10 by a first end and protrudes outside the housing 1 in a watertight manner by a second end opposite to its first end.

This configuration allows heat to be conducted along the second elongated member 6 from the control unit 10 to the outside of the housing 1.

Like the first elongated member 5, the second elongated member 6 may be a rod 6 or may comprise a rod-shaped portion.

Preferably, the

rod

5, 6 or the rod-shaped portion of the first or second

elongated member

5, 6 has a substantially circular cross-section.

The above-mentioned sealing means 13 or 16 may be O-rings, respectively.

In the figures it can be seen that the respective second ends of the first and/or second

elongated members

5, 6 have

slats

8, 9, the

slats

8, 9 being spaced apart and formed parallel to the axis of the first and/or second

elongated members

5, 6.

This configuration increases the heat exchange surface between the respective ends of the first and second

elongated assemblies

5, 6 and the surrounding water once the motorized system is integrated into the vessel 30 and once the vessel 30 is placed in or on water. The strip 8 arranged at the second end of the first elongated member 5 and the strip 9 arranged at the second end of the second elongated member 6 thus form a heat sink, enabling a faster dissipation of heat into the surrounding water thanks to the increased heat exchanging surface.

As can also be seen from the figures, in the example shown, the motorized system comprises a motor portion of the "external rotor" type. Thus, the rotor 2 comprises a rotating cage 2 and the

stators

3, 7 comprise a stationary core 3 arranged inside the cage 2.

As mentioned above, this configuration is particularly interesting because it makes it possible to make the rotation speed of the rotor lower than that of motors of the "internal rotor" type (stationary cage and rotating iron core), by maximizing the diameter of interaction between the coils arranged in the centre and the magnets arranged at the periphery. Thus, this configuration eliminates the need for a retarder, thereby reducing cost and maintenance.

This also overcomes the traditional solutions for cooling motors of the "external rotor" type, for example as a water circulation system in the fixed part of the motor, and its complexity (pipes, water inlets and water outlets in the motor), by resting on the fixed elements (for example the stators 3, 7) inside the casing 1 to take the heat generated by the operation of the motor and conduct it to the outside.

Alternatively, the motorized system may comprise an "internal rotor" type motor element with a rotating core and a fixed outer cage that may constitute the housing 1.

In this case, the first elongated assembly 5 (and possibly the second elongated assembly 6) can rest on the casing 1 itself, which constitutes the motor fixing means, to capture the heat generated by the motor operation and conduct it to the outside.

It should be noted that this description is given by way of example and not as a limitation of the invention.

In particular, although finding particularly interesting applications in the field of surfboards, the invention is not limited to surfboard-type vessels, but extends to vessels such as paddle boards or windsurfing boards.

More generally, the invention is not limited to plate-type watercraft, but extends to any watercraft with electric assistance, such as canoes or kayaks.

Claims

1. An electro-motorization system for a vessel (30), such as a surfboard or a paddle board, configured to be connected to an electric power source, said system comprising a watertight housing (1) for integration into or on the vessel (30), wherein the housing (1) is arranged with a rotor (2), a stator (3, 7) and a shaft (4), wherein the shaft (4) is connected to the rotor (2) by a first end and protrudes outside the housing (1) in a watertight manner by a second end opposite to its first end; said shaft (4) being adapted to be connected by its second end to propulsion means (20), such as a propeller, of a vessel (30) such that, when said system is powered, said rotor (2) starts to rotate and drives said shaft (4) in this rotation, said system further comprising cooling means (5, 6),

wherein the cooling means (5, 6) comprise at least a first elongated component (5) which is at least partly metallic, a first end of which is arranged inside the housing (1), the elongated component (5) protruding outside the housing (1) in a water-tight manner through a second end opposite to the first end, in order to allow heat to be conducted along the first elongated component (5) from the inside of the housing (1) to the outside of the housing (1).

2. The system according to claim 1, wherein the first end of the first elongated component (5) is fastened to the stator (3, 7).

3. System according to claim 2, wherein the stator (3, 7) comprises at least one fastening element (7), such as a fastening plate (7), and wherein the first end of the first elongated component (5) is connected to the fastening element (7).

4. System according to any one of claims 2 and 3, wherein the first elongated component (5) comprises at least a first portion, such as a rod (5), which is integral with at least a portion of the stator (3, 7).

5. System according to any one of claims 2 and 3, wherein the first elongated component (5) comprises at least a first part, such as a rod (5), which is pressed into a housing provided in the stator (3, 7), the housing comprising a paste-like heat conducting material, such as a heat conducting silicone.

6. System according to any one of claims 4 and 5, wherein at least said first portion of said first elongated component (5) is a rod having a substantially circular cross-section.

7. System according to claim 6, wherein the first elongated component (5) is a rod (5) of circular section protruding from the casing (1) in a watertight manner by means of an O-ring (13).

8. System according to any one of claims 2 to 7, further comprising an electronic control unit (10) configured to control the operation and the supply of power of the system and fixed to the stator (3, 7) so as to form a thermal path between the control unit (10) and the first elongated component (5) to allow the heat emitted by the control unit (10) to be conducted to the outside of the casing (1) along the thermal path and the first elongated component (5).

9. The system according to any one of claims 1 to 8, further comprising an electronic control unit (10), said electronic control unit (10) being arranged inside said housing (1) and configured to control the operation and power supply of said system; and wherein said cooling means (5, 6) comprise at least one second elongated component (6) at least partially metallic, fixed to said control unit (10) by a first end and protruding outside said casing (1) in a watertight manner by a second end opposite said first end, so as to allow heat to be conducted from said control unit (10) along said second elongated component (6) to the outside of said casing (1).

10. The system according to claim 9, wherein at least a portion of the second elongated member (6) is a rod having a substantially circular cross-section.

11. System according to claim 10, wherein the second elongated component (6) is a rod (6) with a circular section protruding from the casing (1) in a watertight manner by means of an O-ring (16).

12. System according to any one of claims 1 to 11, wherein the first and/or the second elongated component (5, 6) has slats (8, 9), the slats (8, 9) being spaced apart and formed parallel to the axis of the first and second elongated component (5, 6), respectively.

13. The system according to any one of claims 1 to 12, wherein the rotor (2) comprises a rotating cage (2) and the stator (3, 7) comprises a stationary core (3) arranged inside the cage (2).

14. A watercraft (30) such as a surfboard or paddle board with electrical power assist comprising a propulsion device (20) capable of allowing the watercraft (30) to advance on or in water and a source of electrical energy,

-further comprising an electric motorization system according to any of claims 1 to 13, the watertight housing (1) of which is integrated on or in the vessel (30) and the shaft (4) of which is connected by its second end to the propulsion device (20) in order to drive the propulsion device (20) when the electric motorization system is powered by the electric power source and to cool the electric motorization system by heat exchange between the second end of the first elongated component (5) and the surrounding water.